Ellipsograph



sept. 29, 1931. A, DIETRICH 1,825,444

ELLIPSOGRAPH Filed Sept. 17, 1928 v @Mom/Lug M an/lm Patented Sept. 29, 1931 i ALFON S DIETRICH, OF GLENDALE, LONG ISLAND, NEW YORK ELLIPSOGRAPH Application led September 17, 1928. Serial No. 306,294.

The main object of this invention is to provide a device for scribing ellipsoid or any other irregular or symmetrically shaped outlines. j

Another object of this invention is to provide a compass suitable for scribing any` shape or form of outline, irrespective of its symmetry or irregularity, with the aid of a replaceable master disc which forms part of the device. i

Still another object of this invention is to provide a compass which is capable of scribing symmetrical or irregular outlines of any dimension Within the limits of the instrument.

The above and other objects will become apparent in thedescription below, in which characters of reference refer to like-named parts in the drawings. i Referring briefly to the drawings, Figure 1 is a partly sectioned side elevational view of the compass.

Figure 2 is a top plan view ofthe same. f Figure 3 is an end elevational view of Figure 1.

Figure 4 is a fragmentary perspective view of the scribing beam. Y

Figure 5 is a perspective view. of the adj ustable rail.

Referring in detail to the drawings, the numeral 10 indicates a stud which forms part of the base of the device. This stud has projecting downwardly therefrom a trio of prongs 11, 12 and 13. The prongs are linearly aligned and are adapted to pierce the paper or material upon which the outline 1s :to be drawn. A trio of prongs are used to place the instrument upon an axis of the figure to be drawn and also to center the compass upon the gure being drawn. The st ud 10 has a stem 14 provided thereon which 1nserts into a canal 15 formed in the lower en d of the compass spindle 16. This stem 14 1s secured in place in the canal 15. by a thumb 5 screw 17. The upper end of the spindle has a face plate 18 formed thereon on which is seated a replaceable and special master disc 19. This master disc is provided with a periphery or outline identical with the outline o which is to be drawn by the compass. Surmounting the master disc and secured theretois'an auxiliary spindle 20 provided with a flange 21 at one end which secures directly to the master disc and the face plate 18. At the upper end of the auxiliary spindle a re- 3 duced extension 22 is provided. This reduced extension has' an opening therein into which is inserted the shank 23 of arotatable stud 24. The stud rests upon the upper end of the extension 22, which latter is nonmy rotatable, and is retained in axial relation with the auxiliary spindle 20 by a collar 25 in which-is containedthe stud 24 and the extension 22. Theextremities of the stud 24 and the extension 22 are provided with encircling flanges which form shoulders in the collar 25. This collar 25 retains the stud in position adjacent the auxiliary spindle. The stud 24 has a hinge head 26 formed thereon. This hinge head is slotted and has a downl` wardly extending pointed projection 27 to which is pivotally attached the tongue 28 located at the upper end of a sleeve 29. A finger stud 30 surmountsthe head and has for its purpose to enable 'the Vuser of the device to f grip the compass inconvenient fashion. The sleeve 29 is hollow throughout the greater portion of its length and is provided with a longitudinal slot 31 extending from one end to a position near the tongue 28. Said sleeve member 29 has a `slide block 32`adjustably mounted therein. This slide blockfisprovided with a channel 33 into which one end of a follower fork .34 is pivoted. This forming fork has its opposite ends flared in opposite directions to provide a depression or saddle in which the `.edge of the master disc 19 registers. The slide block -32is normally urged toward the outer open end of the sleeve 29 by` a coil spring 35 which is confined within the sleeve. Below the slide block, and slidable within the sleeve, is a circular shank 36 which has a bifurcated end 37. The bifurcated end 37 of the shank engages and is Secured to one or the other of the tonguesBS o.; or 39 of an I-shaped rail 40. These ears are located on the upper flange 41 of the II-shaped rail and the shank 36 is adaptedto be replaced by another shank of longer or shorter length according to the size of the master dises which are to be used. The rail consists of an upper flange 41, as stated, and a lower iiangc 42 parallel to the upper flange. These lianges have their adjacent surfaces dovetailed, as indicated by the numeral 43, and are connected by a web 44. The web is provided with a slot 45 which extends throughout the greater portion of its length.

The rail 40 is supported on a compass beam which comprises a pair of parallel extending arms 46 and 47. The sides of these arms are dove-tailed and register in the dove-tailed portions of the rail on both sides of the web. The arms 46 and 47 of the compass beam are separated from each other by a channel 48 which channel is open at one end and is closed at the other end. The closed end 49 of the compass beam, where the parallel arms 46 and 47 are joined, is provided with an opening 50 in which a reduced neck 51, Jformed on the lower end of the spindle 16, is received. This compass beam is supported upon the face or" the stud 10 and, in turn, supports the rail 40. A pin 52 is anchored in the separated ends of the parallel arms 46 and 47 of the compass beam and passes through the slot 45 in the rail, said pin servine as a limiting member to prevent the rail irom being detached from the compass beam.V

A ridge 53 projects from the lower flange 42 of the rail. This ridge serves as a guide for the head 54 of a drafting pen 55. The head of the drafting pen is secured to the ridge in any of a number oi' adjustable positions bya thumb screw 5G.

The side of 011e or the other of the arms 46 or 47 of the compass beam may be provided with linear graduations 57 which determine the scale to which the outline of the figure is to'be drawn. To retain the forming fork continually in engagement with the edge of the master dise a spring 58 is secured to the lower end of the spindle 1G and the bifurcated end 37 of the shank 36.

The device is particularly adapted to be used in preparing outlines other than circles, but circles can also be drawn with the instrument. Such irregular outlines as alphabet letters, in script or'printed form, or ellipses, ovals, or cam curves, may all be constructed with this device, to any scale required, within the limits of the instrument.

ln using this device the major and minor axes of an irregular outline are rst laid out. The prongs, which are linearly aligned, are then positioned upon one or the other of the laid-out lines, with the parallel prong 12 piercing the intersection of these guide lines. The master disc desired has, previous to this operation, been mounted in place between the spindle 16 and auxiliary spindle 20 through the medium of the screws 59, and the edge` of the master disc has been inserted into the saddle of the forming fork 34. The upper head 26 of the stud 24 is rotatable about the axis of the auxiliary spindle and, as the head 26 carries suspended therefrom the sleeve 29 in which the slide block 32 is located, the entire structure suspended from the head 26 is rotatable therewith. At the lower end of the spindle 16 the compass beam is rotatably mounted by inserting the reduced portion 51 of the spindle 16 into the opening 50 of the compass beam. This compass beam has mounted slidably thereon the rail which serves the double purpose of an anchoring member for the pen 55 and, by reason of thc` dove-tailed surfaces on the flanges 41 and 42, locks the arms 46 and 47 in place in such manner that these arms will not be damaged, bent or deformed while the device is in use. The spring 58 constantly retains the forming fork 34 in sliding contact upon the outline of' the master disc and thereby insures accuracy of duplication of the outline to the scale desired.

It is to be noted that certain changes in form and construction may bc made without departing from the spirit and scope of the invention.

I claim:

1.' A compass for scribing outlines of predetermined contour comprising a vertically positioned spindle, means for retaining said spindle in stationary position, a disc having` the desired outline mounted rigid with said spindle, a head mounted rotatably on said spindle, a compass beam extending from said spindle and rotatable thereabout, said compass beam extending at rightangles to said spindle and comprising spaced-apart parallel arms thereon, said arms having their side edges beveled convergingoutwardly, an I-shaped rail slidable on said compass beam between the arm thereof, said rail being beveled to lit said parallel arms to prevent spreading of the latter, and means connected to said rail and rotatable head engaging said disc, said disc being adapted to change the position of said rail with respect to said arms as said beam rail and head are rotated about the spindle.

2. A compass for scribing irregular or symmetrical outlines comprising a vertically positioned spindle, means for retaining said spindle in stationary position, a disc having the desired outline mounted rigid with said spindle, a head mounted rotatably on said spindle, a compass beam extending from said spindle and rotatable thereabout, said compass beam extending at right-angles to said spindle and having spaced-apart parallel arms thereon, said arms having their sides dovetailed, an I-shaped rail slidable on and between the arms of said compass beam, said rail being dovetailed to receive said parallel arms to prevent spreading of the latter, said disc being adapted to move said rail, a sleeve depending from said head, a slidable 'follower block in said sleeve, means slidable in said 'les l lill l ifi sleeve connected to said rail for sliding the latter along said compass beam, and means mounted pivotally on said follower block engaging said disc for radially shifting said sleeve.

3. A compass for scribing irregular or symmetrical outlines comprising a vertically positioned spindle, means for retaining said spindle in stationary position, a disc having the desired outline mounted rigid With said spindle, a head mounted rotatably on said spindle, a compass beam extending from said spindle and rotatable thereabout, said compass beam extending at right-angles to said spindle and having spaced-apart parallel arms thereon, said arms having their sides dovetailed, an I-shaped rail slidable on and between the arms of said compass beam, said rail being dovetailed to receive said parallel arms to prevent spreading of the latter, said disc moving said rail reeiprocally, a sleeve depending from said head, spaced-apart tongues on said rail, a shank movable in said sleeve, said shank being pivotally connected to one of said tongues, a slide block in said sleeve, means pivotally mounted in said slide block engaging said disc for radially shifting said sleeve and rail, 'as said rail and associated parts are rotated about the spindle, and means for retaining said second-named means in engagement with said disc.

ll. A compass for scribing irregular or symmetrical outlines comprising a vertically positioned spindle, means for retaining said spindle in stationary position, a disc having the desired outline mounted rigid with said spindle, a head mounted rotatably on said spindle, a compass beam extending from said spindle and rotatable thereabout, said compass beam extending at right-angles to said spindle and having spaced-apart parallel arms thereon, said arms having their sides dovetailed, an I-shaped rail slidable on and between the arms of said compass beam, said rail being -dovetailed to receive said parallel arms to prevent spreading of the latter, a sleeve depending from said head, spacedapart tongues on said rail, a shank movable in said sleeve, said shank being pivotally connected to one of said tongues, a. slide block in said sleeve, a forming fork pivotally mounted in said block, said sleeve having a longitudinal slot therein, and said forming fork passing through said slot and being adapted to ride on the periphery of said disc, and a spring connected to said spindle and said shank for retaining said forming fork in engagement with the periphery of said disc.

5. A compass for scribing outlines of nredetermined contour comprising a vertical spindle, means for retaining said spindle in stationary position, a disc having a desired outline rigidly mounted on said spindle, a rotatable head surmounting said spindle, a

compass beam extending rotatably from said spindle at right-angles thereto, a rail slidable on said compass beam, extensible means pivotally suspende-d from said rotatable head riding upon the marginal edge of said disc; said extensible means being connected to said rail, and means on said rail for scribing an utline smaller in area than 4the area of said isc.

6. A compass for scribing outlines of predetermined contour comprising a vertical spindle, means for retaining said spindle in stationary position, a' disc having a desired outline rigidly mounted on said spindle, a rotatable head surmounting said spindle, a compass beam extending rotatably from said spindle at right-angles thereto, a rail slidable on said compass beam, extensible means pivotally suspended from said rotatable head riding upon the marginal edge of said disc, said linearly spaced-apart ears projecting from said rail, sai-d extensible member being connected to one of said ears according to the size of said disc, one end of said rail being extending under said disc, a bow pen mounted on said rail for adjustmenttherealong, said bow pen being adapted to be adjusted to a position beneath said disc for bounding an area of the same shape as said disc but of smaller area.

7. A compass for scribing outlines of predetermined contour comprising a vertically positioned spindle, means for retaining said spindle in stationary position, a disc having the desired outline mounted rigid with said spindle, a head rotatably mounted on said spindle adapted to be gripped by the fingers when in use, a compass beam extending from said spindle and rotatable thereabout, an arm suspended from said head and movable therewith and bearing against said disc, an I-beam pivotally7 connected to said arm and slidable on said compass beam, said compass beam extending at right-angles to said spindle and comprising spaced-apart parallel arms there on, said disc being adapted to guide the rail in extensible movement on said arms.

In testimony whereof I atlix my signature.

ALFONS DIETRICH. 

